Ion Beam Synthesis of the Anti-sticking Diamond-like Carbon Layers

Ion beam deposited hydrogenated undoped as well as SiOx doped diamond-like carbon (DLC) thin films were deposited and evaluated as anti-adhesive layers. Film surface contact angle with water was investigated as a measure of the surface free energy and anti-sticking properties. Contact angle dependence on the film thickness (7 - 200 nm) and air-annealing resistance in terms of the contact angle with water of the synthesized diamond-like carbon films were investigated. Contact angle of the 9 nm thickness DLC films deposited under appropriate process conditions was the same as one of the thicker (200 nm thickness) DLC films. It is shown, that it is more easy to grow ultra-thin anti-sticking DLC films at lower ion beam energies. It was explained by some ion induced intermixing at the DLC-Si interface. Contact angle with water of the 200 nm thickness DLC films was more sensitive to the air annealing than contact angle of the thinner (24 - 30 nm thickness) DLC films. Surface of the undoped DLC films was smoother than surface of the SiOx doped DLC thin films. 250 min annealing at 200 DGC temperature in air didn't cause any roughening of the undoped DLC film surface. While in the case of the SiOx doped DLC thin film, decrease of the surface roughness was observed as a result of the air annealing.